1. Field of the Invention
The present invention relates to a rinse treatment method of performing rinse treatment on a substrate such as a semiconductor wafer after an exposed pattern thereon has been subjected to developing treatment in the photolithography process, a developing treatment method including the rinse treatment method, and a developing apparatus for carrying out the developing treatment method.
2. Description of the Related Art
In a photolithography process in manufacturing a semiconductor device, for example, a resist coating treatment of applying a resist solution being a coating solution onto, for example, a semiconductor wafer (hereinafter, referred to as a wafer) being a substrate to be processed, to form a resist film, exposure processing of exposing the resist film in a predetermined pattern, heat-processing of accelerating chemical reaction in the resist film after the exposure, developing treatment of developing the exposed resist film and so on are performed in sequence, thereby forming a predetermined resist pattern on the wafer.
In the developing treatment in such a photolithography process, a developing solution is applied to the wafer to form a paddle of the developing solution to cause developing treatment to proceed by natural convection for a predetermined time, and the developing solution is then shaken off. Subsequently, pure water is supplied as a rinse solution, and the developing solution and the rinse solution remaining on the wafer are shaken off, whereby the wafer is dried.
Recently, however, with advancement of exposure technology and so on, the semiconductor wafers become increasingly miniaturized to result in a microscopic resist pattern with a high aspect ratio, which is suffered from problems. One of the problems is that a so-called “pattern collapse” occurs in which in shaking-off drying at the final stage in the developing step, the resist pattern is pulled and collapsed due to the surface tension of the rinse solution when the rinse solution flows out from the pattern.
Another problem is that, with the miniaturization of the pattern, a chemically amplified type resist is used as the photoresist which produces a large amount of precipitates (precipitation-based defects) in the developing step.
As a means to solve the aforementioned “pattern collapse,” Japanese Patent Application Lain-open No. H7-142349 proposes a technical art of mixing, for example, a surfactant into the rinse solution to reduce the surface tension of the rinse solution. Further, Japanese Patent Application Laid-open No. 2001-5191 discloses a process of supplying a surfactant at the time when performing rinse treatment on the substrate after developing treatment.
Besides, to address the problem of increase in precipitation-based defects, conventionally removal of the precipitates has been performed by keeping a longer rinse treatment time.
However, for the problem of the pattern collapse, if the surfactant is used as the rinse solution, there occurs another problem. The problem is that the surfactant permeates into the resist pattern after developing treatment which has swelled and increased in permeability, thus varying the pattern line width (CD: Critical Dimension).
Besides, for the problem of increase in precipitation-based defects, if the rinse time is extended, the throughput decreases to decrease the productivity.